Evaporust vs. wire wheel and buffing compound

[Admiral]

Oh, great, so you can find a metalurgist when you need one!  Hopefully then you can set me straight on this.

I found that statement here, go to the second from last FAQ about the black film, they are talking about carbon migration from the interior of the steel, not from the iron oxide:

http://www.evapo-rust.com/product-info/faqs/
[/url]
[url=http://www.evapo-rust.com/product-info/faqs/]
here's the whole FAQ:

The black film is carbon from the steel. Steel is composed of a combination of carbon and iron. In certain instances, steel will darken in color after rust has been removed from the surface of the metal. This is a natural phenomenon that chemists refer to as “carbon migration”. The carbon from the steel moves, or “migrates”, to the outer layer of the metal and settles into the pores. The removal of the rust (iron oxide) reduces the proportion of iron to carbon, leaving a higher concentration of carbon on the outer surface. This heavier layer of carbon could cause a darkening of the metal due to the attributes of the carbon. The darkening does not have an adverse affect on the metal. It merely represents the movement of carbon from the interior of the metal to the exterior of the metal.


Since Evapo-Rust® is a highly effective rust remover, it stimulates the carbon migration process. Evapo-Rust®is not alone in creating the carbon migration effect. Other rust removal treatments will also result in carbon migration and a darkening of the metal. The primary difference between Evapo-Rust® and the acid based treatments is that Evapo-Rust® will not harm or weaken the metal. Unlike other treatments, Evapo-Rust® will not darken products made with low carbon steel.

With Evapo-Rust®, sometimes a wiping with a dry cloth or a more rigorous buffing can remove the dark coloring. A quick rinsing of the metal after Evapo-Rust® has been applied may also keep the carbon from settling into the pores of the metal.

There are several things that can be tried to minimize the effects of carbon migration. First, high carbon parts should not be soaked longer than necessary. Once the rust has been removed, the parts should be rinsed and dried. Second, a further dilution of the Evapo-Rust® formula may have a positive affect. The lower concentration of Evapo-Rust® will take longer to remove the rust, but may have less of an effect on causing the carbon migration.

[AHill]

Oh, great, so you can find a metalurgist when you need one!  Hopefully then you can set me straight on this.

I found that statement here, go to the second from last FAQ about the black film, they are talking about carbon migration from the interior of the steel, not from the iron oxide:

http://www.evapo-rust.com/product-info/faqs/
[/url]
[url=http://www.evapo-rust.com/product-info/faqs/]
here's the whole FAQ:

The black film is carbon from the steel. Steel is composed of a combination of carbon and iron. In certain instances, steel will darken in color after rust has been removed from the surface of the metal. This is a natural phenomenon that chemists refer to as “carbon migration”. The carbon from the steel moves, or “migrates”, to the outer layer of the metal and settles into the pores. The removal of the rust (iron oxide) reduces the proportion of iron to carbon, leaving a higher concentration of carbon on the outer surface. This heavier layer of carbon could cause a darkening of the metal due to the attributes of the carbon. The darkening does not have an adverse affect on the metal. It merely represents the movement of carbon from the interior of the metal to the exterior of the metal.


Since Evapo-Rust® is a highly effective rust remover, it stimulates the carbon migration process. Evapo-Rust®is not alone in creating the carbon migration effect. Other rust removal treatments will also result in carbon migration and a darkening of the metal. The primary difference between Evapo-Rust® and the acid based treatments is that Evapo-Rust® will not harm or weaken the metal. Unlike other treatments, Evapo-Rust® will not darken products made with low carbon steel.

With Evapo-Rust®, sometimes a wiping with a dry cloth or a more rigorous buffing can remove the dark coloring. A quick rinsing of the metal after Evapo-Rust® has been applied may also keep the carbon from settling into the pores of the metal.

There are several things that can be tried to minimize the effects of carbon migration. First, high carbon parts should not be soaked longer than necessary. Once the rust has been removed, the parts should be rinsed and dried. Second, a further dilution of the Evapo-Rust® formula may have a positive affect. The lower concentration of Evapo-Rust® will take longer to remove the rust, but may have less of an effect on causing the carbon migration.

My take on this is the carbon that's deposited is the leftover carbon from the chemical conversion of the rust.  It's not coming from the base metal.  That would be consistent with the chelation chemical process.  It doesn't darken low carbon steel, because there's not enough carbon in the rust to make that much of a color difference after chelation.

[omark]

> How did you brighten up the metal after an Evaporust bath?

Try thin brass wire wheel (not to be confused with brass covered steel), like 6inch offered by LeeValley.

[JimReed@Tallahassee]

I live in N Florida and deal with lots of rust in my shop. I have many vintage tools and most of them have rust. Rarely does a day go by that I do not knock some rust off of steel. The result is always a black spot. It is a familiar sight in my shop. All of that background makes chemically cleaned up tools stand out in my shop. Plane blades are OK because they are covered up. Chemically treated saws, however, just look ugly. I prefer the rust over the gray boiled beef look.

[AHill]

I queried Evapo-Rust about the "carbon depletion", and this was there response:

"Evapo-Rust does not cause Carbon Depletion, it will only target IRON. As Steel consists of Iron and Carbon, when Iron(rust) is removed a slight migration of carbon fills in the pores on the surface of high carbon tools like handsaws, chisels etc. during the de-rusting process. This does not alter the strength of the metal. The excess Carbon can be removed by lightly scrubbing the de-rusted item with the Evapo-Rust solution before removing from the dip tank.


Evapo-Rust will not change the integrity of the metal in ANY WAY as it will not target the base metal. Razor sharp items will be just as sharp upon removal of Evapo-Rust as they were previous to de-rusting. I personally have de-rusted hundreds of saws with absolute confidence. Evapo-Rust WILL NOT alter the performance of the saw in any way."


I hope this helps.  This is pretty much how I interpreted their statements in their FAQ's.

[Tynyyn]

The excess Carbon can be removed by lightly scrubbing the de-rusted item with the Evapo-Rust solution before removing from the dip tank.
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I've lightly scrubbed my saw blades with steel wool before I take them out of the tank and they are still coated with the gray deposits. After using Evaporust and seeing the coloring results and then hitting the blade with a wire wheel, I am becoming a believer that Evaporust DOES NOT help in the appearance of the blade, rather takes away from the shininess. Evaporust is a great product for getting rust off of metal, but if you want to make that metal shiny, then I have to say stay away from Evaporust unless you want to use a lot of elbow grease.

I did have great hopes for Evaporust and looked high and low for a bottle of it. But I have been disappointed. It does exactly what it says it does. It just has a different kind of result I was not expecting. Oh well, one tries different thing in order to experiment to see if a product is better than another and I will keep on experimenting. One thing is for sure, Admiral has "been there and done that" longer than me, so I think I will follow his advise and go back to the old ways of sand paper, water type solution, and scrubbing.

[WoodTinker]

This begs the question.

Do gray metal objects (saws) after Evapo-Rust treatment fair better in the long run than shiny saws cleaned by a wire-wheel or other product from rust? A little wax and I'm sure they both cut the same. Carbon has less friction then metal.

If the pores are covered in carbon then that metal object must have a less likely chance of rusting in X amount of time. A highly polished surface has a different X amount of time to rust.

Which is better? Look vs Function?

[AHill]

Just my opinion.  I don't use Evapo-Rust on saw plates.  I don't like the gray on the surface, and it's a lot of work to remove the gray to get it back to shiny.  I think a minimalist approach is necessary there.  I have used it on plane bodies and even on plane blades, and yes, I've seen the gray coating it leaves behind.  It does take some effort to remove the gray.  The gray does not seem to affect the function or performance of any of the tools I've de-rusted with Evapo-Rust.  I think reducing the soak time would help to reduce the amount of carbon deposited on the tool surface.  If you are using recycled Evapo-Rust, then perhaps passing it through a filter would remove some of the carbon suspended in the solution from previous de-rusting attempts.  I don't know of a better rust remover than Evapo-Rust, but users should be aware of its limitations.  If you want shiny, then stick with mechanical removal, electrolysis (which DOES attack the base metal), or acid removal (which DOES attack the base metal).

[Timberwolf]

I enjoy restoring old handsaws.  The way I make the blade rust free is to run the blade underneath an 8" brass wire wheel attached to my grinder.  Then I use green buffing compound on a cotton wheel and after a half hour the blade seems bright and rust free.  I've done about ten blades and have been pleased with the success.  Though holding the blade under the wire wheel to knock the rust off is getting a bit tiresome.

So the other day I went to HF and picked up a gallon of Evaporust because I've seen youtube vids on its effectiveness and have seen testamonials on here and other forums.  I simply put the blades in a container of Evaporust and waited 24 hours and sure enough the rust just wiped off. 

My conundrum begins when I put the blades to the buffing wheel.  I used black, white, brown and green buffing compounds and was unimpressed with the results.  It seems that the evaporust left the blades with a gray coating and the buffing did not take the gray coating off. 

Has anybody else experienced this condition of the gray coating being left on their metal parts dipped in Evaporust?  What did you do to get that stuff off the metal?  How did you brighten up the metal after an Evaporust bath?

.........................
The "gray" color left by Evaporust is the reason I stopped using it..I use a strong solution of vinegar or a saturated solution of citric acid to remove rust , followed by a "soft" wire buffing wheel...The wheel I use is a one inch thick 6" diameter wheel from a jewelry supply that I bought years ago.. The steel wires are very small diameter {like hair} and wont leave the "orange peel" finish on cast iron. Instead, it has the effect of leaving a slight "polish" on the surface. I like to run the wheel at 1725rpm. Higher speed has a more aggressive effect...On hardened steel, I use a Cratex Bright-Boy or 3-M deburring wheel charged with aluminum oxide, running at 1725rpm....The deep "pitting" in the surface caused by the removal of rust can't be removed by any "practical" means I know of.
I have also use emery on a hard-stitched muslin buffing wheel which I run at 3450rpm..and it works pretty well also...

[Tynyyn]

TW, thanks for your input. I will google all the examples and see which ones I have and which ones I need. You are a good man.